1. Field of the Invention
This invention relates to a novel class of heterocyclic compounds useful for selectively inhibiting chymotrypsin-like enzymes, selectively inhibiting elastase or for generally inhibiting serine proteases of many classes. We have found that isocoumarins substituted with biotin and hydrophobic groups are potent inhibitors of chymases, elastases, and other serine proteases. These biotinylated isocoumarins can be used to selectively or generally remove proteases from solution or biological systems. They can be used either selectively or generally to isolate serine proteases. They can also be used to selectively or generally inhibit serine proteases either in vitro or in biological systems.
2. Description of the Related Art
Serine proteases play critical roles in several physiological processes such as digestion, blood coagulation, complement activation, fibrinolysis, viral infection, fertilization, and reproduction. Serine proteases are not only a physiological necessity, but also a potential hazard if they are not controlled. Uncontrolled proteolysis by elastases may cause pancreatitis, emphysema, rheumatoid arthritis, bronchial inflammation and adult respiratory distress syndrome. Human polymorphonuclear leukocyte elastase may also be involved in blistering. Accordingly, specific and selective inhibitors of these proteases should be potent anti-inflammatory agents useful in the treatment of protease-related diseases (Powers and Harper, in Proteinase Inhibitors, Barrett and Salvesen, eds., Elsevier, 1986, pp 55-152, incorporated herein by reference). In vitro proteolysis by chymotrypsin or the elastase family is a serious problem in the production, purification, isolation, transport or storage of peptides and proteins. It is often desirable to remove all proteases from solution or biological systems. In other cases, it is desirable to isolate or remove a specific serine protease.
Anti-inflammatory agents are used to treat elastases-associated inflammation including rheumatoid arthritis and emphysema. Although the naturally occurring protease inhibitor, .alpha.1-protease inhibitor (.alpha.1-PI) has been used to treat patients with emphysema, this inhibitor is not widely used clinically due to the high dosage needed for the treatment and difficulty of producing large quantities. Therefore small molecular weight elastase inhibitors are needed for therapy.